Air charger



Aug. 17, 1948. L. E. GORDON AIR CHARGER Filed Dec. 2l, 1945 n IN VEN TOR. LEO/YARD E. 60.@00/5 Patented Aug. 17, 1948 UNITED STATES PATENT OFFICE 2,447,173 y y s Am CHARGER Leonard E. Gordon, Oakland, Calif. Application December 21, 1945, Serial No. 636,397 v 11 Claims.

This invention relates to devices for introducing into closed containers, such as liquid storage tanks, quantities of air sufficient to provide an air cushion above the level of water in the tank.

An object oi the inventionis to provide, in apparatus of the character described, novel mechanism which is motivated by the flow of liquid from the container for injecting air into the container against the resistance of fluid under pressure which is already present in the container.

Still another object of the invention is to provide in a water storage tank, provided with a side inlet for admitting air, means operative to force air into the tank through said inlet even though the water in the tank covers or extends above the level of the inlet. s

A further object of the invention isto .provide a mechanical air charger which is not liable to become fouled or clogged by the presence of sediment in the liquid.

The invention possesses otherobjects and features of advantage, some of which, with the foregoing, will be set forth inthe following description ofthe preferred form of the invention which is illustrated in the drawings accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claims.

Referring to the drawing:

Figure 1 is a view partly in side elevation and partly in vertical section showing one form of the air charger of my invention connected with a storage tank. y

Figure 2 is a vertical sectional view of the charger motor showing the plunger thereof in the position it occupies while liquid is being withdrawn from the container. Y

Figure is a side elevational view, partly in vertical section, of one form of liquid-actuated piston.

Figure 4 is a partial vertical sectional view of a modified form of charger motor.

The apparatus of my invention is particularly adapted for use in domestic water supply systems in which pressure is supplied and maintained by means of a power-driven pump or the like in order to maintain the constant pressure Adesired at various service outlets so as to insure an adequate volume of flow at all times regardless of whether or not the pump may be operating. In many localities, especially in outlying districts not served by the constant pressure mains rof a public utility company, water for drinking purposesand other uses is drawn from still` water sources such as remotely situated springs or wells, the aforesaidY power-driven pumps being employed for conveying the water to thel house'v service mains and for elevating the pressure in f thev mains to produce the .aforementioned sufciency of flow when one or more faucets or other outlets are opened in thesystem.y Due to the fact that the frequency oi'water withdrawals and the quantity of water required at leach withdr-awal may vary widely from time to time, sometimes hours elapsing between demands, it would be obviously impractical tokeep the pump running continuously to maintain theline pressure since this would lcause undue wear in the pump and motorandunnecessary waste of power. It is common'practice in such water supply systems to providea storage tank or accumulator intermediate the pump and the house mains capable of holding under pressure a considerable quantity of previouslyr pumped water which may be periodically replenished by the pump as a predetermined quantity of water is withdrawn from the tank. f

In such a tank, a volume of air is maintained at the top thereof above the water which serves as a compressible cushion yieldable as the :water level rises and falls between high and low positions in the tank and at which positions, respectively, the water supply pump may stop and start in response to the operations of a control switch actuated by present high and low pres-v sures of said air cushion. This air cushion besides serving, when compressed, to effect ejection of water;from the tank has a bearing on the frequency of, pump operation since, if 4a comparatively large volume of air is present in the tank, a correspondingly largevolume of water will flowv from the tank between'stops and starts of the pump. Due to minute leaks in the tank or to progressive absorption of lthe lair by thel water due to the air molecules being held between water molecules, muchhfin the same mannerthatwcarbonic acid gas lvis absorbed in the manufacture of charged water, the air cushion will, in time,` completely vdisappearrresulting in* so-called waterlogging and actuation of thel pump control switch each time that a faucet orl other outlet is opened in the service line. It is thus apparent that replenishment of the air lost as explained above is imperative in order to maintain proper operation of the Water supply is a water outlet nipple 1 to which is threadedlyl engaged the upper boss 3 of the air charger housing 9 which is also provided With a lower "boss II preferably diametrically opposed lt .the boss Cil 3 and situated several inches belowl the hori'- Zonta] plane of the latter. Theboss =II lmaybe threadedly engaged with a dispensing faucet I as shown, or the latter may be replaced'by -a'- suitable service conduit. Both bosses 8 and II lareprovid'ed .with-axial 'passages I2 and I3 respectively, which are in communication with a cylinder bore I4 fformed `laxiallyof the housing andfhaving fan `abutment uH3 ymarking its lower end. The housing is'alsoiprovided-with a well :I "I :forming fan i. axial 'extension `of the lower lend of thecylinder bore. IThe'upper. endof'thecyb inder'borefis'threadedto receive a cap I8:=cen trally 'bored 'to form acylindrical air `chamber |19 whichisin axial alignmenty with thecylinder bor-aand whichhas a closed-upperend drilled and fth'readed 5to `'receive a `standard fitting 2 I. lf'r'desired,` I'both .cylinders j could 'be embodied in a'zsin'gle casting. Provided in the cylinder bore I4fis awater piston 22 having .a recess .-23in its bottomf surface which serves as` centering Ymeans for -a ycoilspringll. interposed between lthe lower end `of 'the well Hand thepiston so as'to forcibly urge 'the latter upwardly in the bore 'If4. JIhe piston '2'2,'itlwi1l 'benotedfinFigures'l andf2, is slightly smaller in fdiamete'r than the bore in which itmoves .-s`o asv toprovid'e around theipiston azperipheralLgapZB .which should be'of sufiicient fst widthato-'permit liquidto bleedpast "thepiston Actiialpractic'e 'has :shown: that the gap has a direct bearing on the operational characteristic-s of vxthe charger and 7'depends 'in considerable measure yon ythe'sizey of the ipiston, the f'required velocity of now, inherent lfriction in the moving parts, A'and other ifactors. SHowever, vunder l ordinary vconditions;thewgap may range betweeniive and tenzthousandths -of "an inch which will produce satisfactoryresults inloper'ation. `It will be seenthat thetperiphe'ralfv-.gap between the piston 22s5and fthe bore I-,din whichfthe'form'erI operates is-ofsuchsize 'tirata deliberate, controlled leak-- age ofrwaterI past-the pistonmay occur. Secured to zthe.piston,22, asan integral'part thereof or otherwise, is a rod 'Z'Vextending .concentrically upwardly intozthe air. chamber 'I9 and-having a shouldered and'threaded extensionZB `atlits upper-end 'which :carries an air-piston comprising a :pairof washers 29 {andl between Vwhich is secured Ia Cupleatherfz vwhose-peripheral flange en-gagesxthe air chamber sidewall. The washer 3Iserves asA afsecu'ring nut-forthe .cup leather, being in threaded ,engagementwith the threaded exten-sion -2-8. The type :of `mountingshown is purely exemplary as .other arrangements may be employedgwhich twill suggest @themselves to those skilled :in/the Vart vto v'which the invention pertains.

Projecting fromfthefside offthe tank:6,pref erablyIin yvertical planar alignment fabove the 4 outlet nipple 'l and located at about three-fths of the height of the tank, is an air inlet nipple 33 having an internal thread 34 which provides connection to the nipple of the correspondingly threaded stem 3S of a valve housing S'I. Provided in the housing 37 is a passage 38 which communicably intersects a larger passage 39 perpendicular thereto and extending completely through the housing. The end of thepassage 38 opening within ithe tank n'56 is 'formed iwith an yenlarged. counterbore 4I `having a frusto-conical bottom providing a seat 42 for a ball valve 43 which is retained in, although permitted a limited amount ',offmovement axially of, the counterbore by the provision in the latter of a diametrically extending pi'n-M. The upper end of the passage 39 'is tapped .to --threadedly receive a spring pressed check valve 46 arranged to permit only unidirectional now of air into the passage from the atmosphere and comprising a standard type vof valv'esimilar to atire Valve'and housing. The lower end,v oflthe passage `35) is also-tapped to receivei'a :compression :fittingfdl similar to the t- .tingxZ'I and '.both'ttings are interconnected by a suitable length of tubing 48 ywhich'provides flow `communication 'between the air chamber I5 and thepassagesr and F39.

Referringfto Figurel, the apparatus is shown inits normalfcondition-of repose'when-no .water is being drained fromthe tank. When an outlet in the service line, or the faucet IIJ, is opened Ithe resultingiow of Water from the outlet nipple 'I into thefcylinder bore^|4 due to the sudden reduction of :pressure on the underside of the piston-22 will Acause downward pressure on the piston 22,fcommensurate with :the difference in exposed area between Ithecon'fronting faces of the cair. and water pistons, twhich will cause -the latter to'descendfagainst the counter pressure of the`spring24 until the ywater piston reaches its lower limit of travel as indicated in Figure 2, whereupon the water flow lmay continue directly from the `tank :into the :service line -or `faucet.

:Althoug'hthe chamber lbelow the piston r`22, when the apparatus is Vin -a state of repose as showninFi'gure '1, isille'dfwith Awater which has leaked through the-passage v26 during the vperio'd of inactivityof *the device'and which is under the same head 'ofpressure as the water above the piston, theflow'er chamber pressure willldrop instantly to a reduced-value as soon as the'faucet I is opened. Sincetheupper effective area of the piston 22 ismuch greaterthan that of the air piston confronting it, the total downward pressure on the former caused by the Vwater `seeking to escape from the tank will be-much more than .the f upward y pressure .against the air piston. Consequently, :the water piston will move A d'ownwar'dly'sin'ce Athe onlylresistance it `hasto overcome is that of the spring 2-4, until its lower edge registerswithlthe lowermost point on the periphery'offthe.dischargeaperture 49. From this point downwardly, the movement of the'piston will be cushioned-'due Vto vthe entrapment-of Water in the well -I'I'and the action of the water bleeding'upwardlythrough the gap passage-26. IeIoweverffduey tothe'fact that the piston 22 has lesslvertical-thickness than the diameter-of the aperturef4'9, Whenltl'ie above-mentioned registry ofthe piston and aperture occurs, the upper part of 'the aperture #will beuncove'red so that water from thetank m'ayiiow directlyinto and through the faucet' |10. Thelpressure-"on top'ofthe piston 22Will be 'sui'iicie'nt to continue moving the latter into the faucetor service 'level is below the check valve, the latter vwater tending to close the cover the aperture 49.

downwardly until the aperture 349 is substantially completely exposed to admit water fromthe tank line with a minimum of impedance.

e vI't willfbeseen ofcourse that the downward-movement ofthe water piston 22,* the air 1piston will move correspondingly which will establish Va partial vacuum in the conduit 48. At ythis point, if the water c in the ktank is above the check valve :42, the water seeking to.` enter the of the downwardstroke `conduit' 48 will close the check valve at thel start` of the air piston. As, the

lstroke continues itl createsthe aforesaid partial vacuum in the conduit 48 drawing atmospheric air through the atmosphericcheckVvalvei ,c Qn thev .upward stroke-of the air` piston which is p owered by the expanding springn A,is closed and as avresult of the difference in total ypressures on the 24y when the .valve l0 water and air pistons, respectively, thel air drawnvinto the air cylinder will be forced past the check. valve 42 into the tank until 4suflicient air=collects in the tank to force Athe water level below the check valve and thus replenish the air cushion. However, if the water will remainopen duetto the absence of the weight of check-valve. Thus the air in the tank will pass the check 42 and ill the conduit v48 and consequently will fill the `airchamber I 9. This vair will be returned to the tank during the upstroke of the air piston. Thus no additional air is introduced intothe tank and vthe rair'volumetherem is always kept constant.

It will be noted that when the apparatus is in a stateof repose, 'as shown 1n Figure l, the' of the cylinder l'4 under- `water piston and its cy-linder borefthis water y Awould be irrelievably pocketed and would prevent further descent of the water piston to fully un- Toalleviate this condition, I have developed several methods of relief among which is the provision' ofthe peripheral gap r26l around the waterl piston,as explained above, whichvwll permit the trapped waterto flow upwardly past the piston and eventually vout of the discharge aperture. .'I'herate at which the water may escape isof 'importance,since itis not desirable to unduly retard lthe descent of the water piston to its full*` extent and yet it is also not desirable to create a knock which might occu'r if the piston wereV allowed to descend forcibly against the abutment I6. Still another feature of advantage connected with .the peripheral. gap type of water pistonr is that fine silt which may be'contained in the water,v and whichpmight accumulate to the point of jamming a `tighter piston, jwill not lodge in the gap, -since the repeated forceful water flow therethrough will flush it out.

In Figure 3, I have shown a modified form of water piston 5| designed for snug vring engagement with the cylinder I4 by virtue of akradially expansive piston ring 52vmounted in av peripheral groove 53 lformed in the piston. 'Ihis type of piston could have a greater than the previously described type `soas toovercome friction which might be.v caused by coarse degree of clearance 4sand lodginginthe peripheral U gap surrounding l l1, andthe .portion of the chamben just above the well, may be had throughy one or more passages 54 to ya `.certain .degreeA through the gapy 56v in the f A bleeder drilled through the piston and also piston ring.. Suchaidesign, however. requires thatthe effective area ofA the .piston be` increased slightly in proportion to the resistance of the .spring 24.inordertoQcompensate for theslight frictional dragwhiclji will vbe createdbythe piston ring. ,f t

In Figure 4 Ivhave shown another method of relieving, the trapped water. In this modifica- 21011. the Piston vil may be mada comparatively snug, althoughfreely slidable, in the bore 1 4. The piston is provided with.` a central"y aperture 58, having a flared bottom` portionA 597 and with a plurality of radiallyudisposed ports Gl rvwhich are drilled completely through andiparallelto the axisof the-piston and open. into thewell throat. An annular groove 62, circumscribingfthe group of portsGl andprovided with a threaded outer sidetS,A is providedwin the piston to-receive the threaded annular portion 64 of;.aj1bellshaped cageBG formed onlthe lower endof the rod. 21 and having cutouts ,lfwhichidivide the cage into a plurality of armsrilSf-form'ing retainers fora valve disk 69, of rubber or other suitable material, which functions as a valve normally adapted lture 58 and the portslil.v Thelower end ofthe Well portion of lthe housing is tappedftoy receive the threaded portion- 1| of -a triprod 12 which extends upwardly into 'and inaxialfI coincidence 'with the cylinder '|4.- In this arrangement,` when 'through the'ports andrto be discharged through the' outlet passage 49. I claimtv. l .v

1.`In combinationwitha water supplyyltank,

`a`n air charger having anv air chamber ,in coin- 'munication'jwithi the atmosphere and with vsaid tank,I means in said' .airv chamber operative ,by

lflow of water `from Vsaid/tank for drawing air intol said air chamber, and means associated with vsaid. air drawingmeans operative upon cessation of said vwater'liow for forcing the air in the air chamber into said water supply tank. f v 27 In combination with a water supply tank, an air charger` having an air chamberand a water cylinder associated 'therewith .through which water drawn from the storagel tank may flow, means inthe water cylinder and responsive to flow of water therethrough for drawing air into saidair'chambenand means operativeupon v l cessation of water iiow through saidwater. cylinder,andassociatedfwith said flow responsive means for vforcingairwithin the air chamber into said supply tank.

f v3. In combination with fa water supply tank having vanv ]"outlet adjacent; the bottom4A thereof Jannie-e :may 'ow f romthe outl'et, and aiiaiially aligned '2i-ir L'Cihamber; Spad .irltfneercied Pistons in safid lWater cylinder and air chamberahd movable axially thereof, one of said pistons kbeing movable '-by th new vof yvater passing through sajld yvatercylinder and Ythe other piston` being correspondingly movable lin said airV chamber to draw air threinto, an `air lin connected with said air chamber, means associated v'vith said [pis 'iis' and operative vupon cessation o'f ow ltlrj ugh said 'yvaterfcylinder to 'force the air in 'the lair chamber into said 'air line, and means y-for connecting said 'air lineto' receive 'air'frdm the v'atfrnospheie andvto discharge air into said tank inlet.

4 combination with a 'Water supply tank ing" an :outlet adjacent- Ithe bottom thereof v'and an inlet adjacent thetop thereof, an air `charger comprisingahousing having' therein 'an air 'chamber and afn associated Water cylinder, :said housing lbeing connected vvitliv sai'd outlet 'and -`sfaid \vater cylinderfbeing 'in flovv relationship vWith said outlet, aservicef line havin'g'a" passage ventering said water cylinder, valve housing conifiected insa-id tankinletandprovided with 'intersecting passages, a yl`r"st"of said passages being in communication through fa'check valve A"Wlth-'Sali'dftank and a second of Av said passages being. in communication through an atmospheric :check .valve with the atmosphere, an -aii line 1'conr'iectinglsaid air chamber fand saidsecond Yvalve,r housing passage, means Yin said Water cyl'- :inder andairfchamber movable in accordance .witnwater-ow from said outlet into said service klinefordravving ,air through fsaid atmospheric checkv valve and saidairlilin'e vrintovsaid 'air cham'- jber, vand means connected with said .movable means and operable upon,cessa tion,of `Water. flow 1for forcing the air -in the air chambr `throfi'igh theyair line, the first of, said valve housing Das'- jsagens, vand the che ck val v e t her e ir'1,V yinto .said ,tank through the inlet thereof.

5. -`In combination v with a Water-supply tank having anjoutlet adjacentthe bottom. ,thereof aninletadjacentthe top thereoi an air "ger comprising a -housing hailing-therein an an"associated,.vvatercylinder,

air chamber and: said housing connected with said 'outletandr s aid Water cylinder being inl ow relationship with s autres siervieeiie havigaijassg enter- 'ing saidjwat'e'r cylinder, yal fnectd "i'nj'said tankinl'tfand .provided W'ithfinltersectingpasfsages, 'a first "o'f fsa'i'd Passagesfbei ng in^communication through a Acheck valve with said `tank and asecondv of saidpassag's ybeing fin 'communication 'through an 'atmospheric -check v'alve with the atmosphere, "an 1 irflin'ey connecting said air chamber '-and said secnc'i'jialye"h'o'ising npassage, interconnected Water 'and a;r 'pistons respectively'in and movable along saidfyater cylinder and air chamber, said Water'pist'on 'being ynicivak'ale in 'th'e waterlcylinder infaccordance'yvith the-o'w of fwaterfthrough 'the `cylinder between 'said tank outlet andftheservice line', 'saidwater -'i's-ton during `its `Infovemerit v "eo'rre sriofndi ngly moving said 'air piston in"'the air chamber to 'dawfinto the enainbianiosphri airthrcugh said 'atmospheric check val'V d said Iair rline, and means operable upon cssatio'nf 'Water How thefcheck'valve therein, into said' tank through the inlet' thereof.

' "6. In'cmbi'nation with a water 'supply tank having an outlet adjacent the bottoni thereof and an inletfadjacnt the top thereof, an yair charger comprisinga housing having therein van air 'ehanibe'and an associated water cylinder,V said housing connected with said out-let" and lsaid viater"cylinderv being in VW relationship with said'outlet a service line having a passage enterii'ng said Water lcylir'ider, a valve housing con-- nected in "said tankinlt and `provided with inter'- `secting passages, arst of said passages -`being lin communication through a check 'valve With vsaid'tank 'and 'a second `of said'passages vbeing ough an atmospheric check vvalye7 with the atmosphere, an air line'c'onnectin'g "s'aid air' chamber 'and said second valve housing passage, interconnected water and "air vpistons :respectively in and movable along saidtvater cylinder and air chamber, said Water piston vbeinfgm-ovable in thew'ater cylinder in accordance with the ow''oi water through the cylinder lbe"- tvfeen Asa'id'tank outlet land the service line, said tvater Ipiston during its movement correspondingly'moving said air' piston in the air chamber "t` vdraw` 'into the chamber atmospheric air throughsaid atmospheric check Valve 'and said air line, and asprin'g interposedbetween said lwater piston and said :air charger housing for "moving said pistons upon cessation `oi water flow soas Itofforc'e tl'ieair'inthe air chamber through t he 'air line',` the first of 'said valve passages and the 'cheekyaivethereim into said tank" through the inlet thereof. 'If Incombiiationwi'th a watersupply tank havirlgan utl'etadjacent the bottom thereof andan" inlet" adjacent the top'thereof, an air fha'rger 'comprisinga housing having therein a v vg/fe'r cylinder, providedfwith a 'continuing' Well bordered by anV abutment forming the'lower end of the c zylin-der,v and an axially aligned air cham*- ber, said-housing being connected With said `outlet and said -W-ater cylinder being in floW 'relationship with `said outlet, a service line' having a .passage enteringgsaid Water cylinder above the said abutment, thereof, a valve housing connected in said tank inlet vand provided with `a verticalpassage 'extending therethrough" and a 4lrorizontal passage intersecting said verticalpassage-3nd `entering said tank, a -rst checkvalv'c in saidhorizontalpassage for conning" flow of fluid in lthe passage"unidirectionally into the tank, a A'second check valve 'fin the vertical passage fo'r conningfiow of fluid "unidirectionally `from the'fa'tmosphere in'to 'said 'Vertical passage, a'r'air"li'r1e 'connectingsaid vertical passage and said a'irichamber, li'ter(':"onn'ec`ted /wa'ter andair pistons respe'ctively'in and vmovable"axially "of said Water'cy'linderand'air chamber, said pist'ns 'being' "movable "in "accordance" with' Water ov'v 'through the 'watereyiinder ffrorn thetank outlet Ito saidfse'rvice 'line passage, said'movement be'i'ng 'nmited'by'enggernent of the water 'piston with said abutment bordering the well and said air `pistondralv/ing fair through said lvertical passage 'check-valve-ard s aidair lirieinfto said airh'ambefineahsieomecteawith said water bistori'and operative' upon cessation of :Water iiotv for 5movirig "said stons tuto fi'ce the air in 4the air cham- Lber ugh thelair line, vthe horizontal V'passage 'and'jthe ciieek valve associated fuierewith ihm `s'ai'd ft'ank, jandIr'1eai`1s*operative `Wh'erf'sacid Water anni@ piston is `in engagement withsaid abutment for ventingsaid wen. l I C. ,j In combination with a water supplytank having .an outlet adjacent Athe bottom thereof and an inlet adjacent the top thereof, lan air charger comprising a h', using havingA therein a water cylinder, provided witha continuing, well bordered by an abutmentforming the lowerL .end of tlyiecylinder,l and an axially aligned air vcharnber,"s"aid housingv being connected with said outlet and saidwater;cylinder` rbeingfin flow relationship with said outlet, a service line having av passage entering said water cylinder abovefthe said abutment thereof, a valve' housing connected in said tank inletand .provided with a vertical passage extending therethrough and ahorizontal passage intersecting said vertical passage and entering'. said tank, a first-,chekvalvei lsaid horizontal,- ,passage for conflningsflow of VWM Y the passage unidirectionally into the tank, a second check valve in the vertical passage for coniining flow of iiuid unidirectionally from the atmosphere into said vertical passage, an air line connecting said vertical passage and said air chamber, interconnected water and lair pistons respectively in and movable axially of said water cylinder and air chamber, said pistons being movable in'accordance with Water flow ythrough the water cylinder from the tank outlet to said service line passage, said movement being limited by engagement of the water piston with said abutment bordering the Well and said air piston drawing air through said vertical passage check valve and said air line into said air chamber, means connected with said water piston and operative upon cessation of water flow for moving said piston to force the air in the air chamber through the air line, the horizontal passage and the check valve associated therewith into said tank, and said water piston having a gap extending peripherally around'andbetween the piston and the water cylinder through which water may flow from the well into said service line passage as said water piston approaches said abutment.

9. In combination with a water supply tank having an outlet adjacent the bottom thereof and an inlet adjacent the top thereof, an air charger comprising -a housing having therein a water cylinder, provided with a continuing well bordered by an abutment forming the lower end of the cylinder, and an axially aligned air chamber, said housing being connected with said outlet and said water cylinder being in flow relationship with said outlet, a service line having a passage 'having an outlet adjacent an` inlet -adjacent the-top thereof,;an air charger 1b e througlifsaidhvertical passage check valve and said air line into .said air chamber, means connectedwithsaid water piston and operative upon cessation'."of waterlflow'for moving saidpiston to forgetheairfin theA air chamber'through Vthe air line, .the horizontal passage and the check valve associated therewithfintojsaid. tank, and said water'piston-having therein an f aperture ltlfirough whichrv water maygflow from thevwell 4into said serviceA line passage as said` waterpiston ap-- p roaches said abutment.v i

l0. :In combinationwitha ,water supplyy tank the bottom thereof and comprising a` housing'V having therein a Water cylinder, provided with a continuing .well bordered byingan abutment formingthe lower end of the ifdfin f cylinder,- andan axiallyy aligned air chamber, said housing being connected with; said outlet and said Water cylinder being in flow relationship with said outlet, a service line having a passage entering said water cylinder above the said abutment thereof, a valve housing connected in said tank inlet and provided with a vertical passage extending therethrough and a horizontal passage intersecting said vertical passage and entering said tank, a first check valve in said horizontal passage for confining flow of iiuid in the passage unidirectionally into the tank, a secondy check valve in the vertical passage for conning flow of fluid unidirectionally from the atmosphere into said vertical passage, an air line connecting said vertical passage and said air chamber, interconnected water and air pistons respectively in and movably axially of said water cylinder and air chamber, said pistons being movable in accordance with water ow through the water cylinder entering said water cylinder above the said abutment thereof, a valve housing connected in said tank inlet and provided witha vertical passage extending therethrough and a horizontal passage intersecting said vertical passage and entering said tank, a first check valve in Saidhorizontal passage for confining flow of fluid in the passage unidirectionally into the tank, a second check valve in the vertical passage for conining flow of fluid unidirectionally from the atmosphere into said vertical passage, an air line connecting said vertical passage and said air chamber, interconnected water and air pistons respectively in and movable axially of said water vcylinder and air chamber, said pistons being movable in accordance with water flow through the water cylinder from the tank outlet to said service line passage, said movement being limited by engagement of the water piston with said abutment bordering the well and said air piston drawing air from the tank outlet to said service line passage, said movement being limited by engagement of the water piston with said abutment bordering the well and said air piston drawing air through said vertical passage check valve and said air line into said air chamber, means connected with said Water piston and operative upon cessation of water flow for moving said piston to force the air in the air chamber through the air line, the horizontal passage and the check valve associated therewith into said tank, said water piston having therein ports through which water may flow from the tank into said service line as said water piston approaches said abutment, a valve normally closing said ports, and means engageable with said valve during movement of the water piston for opening said valve.

l1. In combination with a water supply tank having an outlet adjacent the bottom thereof and an inlet adjacent 'the top thereof, an air charger comprising a housing having therein a water cylinder, provided with a continuing Well bordered by an abutment forming the lower end an axially aligned air chamber, said housing being connected with said outlet and said water cylinder being in flow relationyship with said outlet, a service line having a passage entering said water cylinder above the said abutment thereof, a valve housing connected in said tank inlet and provided with a vertical passage extending therethrough and a horizontal passage intersecting said vertical passage end entering said tank, a iirst check valve in said horizontal passage for confining flow of fluid in the passage unidirectionally into the tank, a second check valve in the vertical passage for confining flow of fluid unidirectionally from the vatmosphere into .said vertical passage, an air line 11 connecting said vertical passage and said air chanber, interconnected" Water and air 'pistons resiiecti'vebfV in 'arid 'movable axially' of' said Water cylinder and 'air'V chamber, said pistons 'being :navali-1e in accordance 'with Water fiom/through the' jvv'ater cylinder frojm th tank' outlet to "said servi'celine passage, said movement 4being limited byengagement of the' Water piston with 'said abutment bordering' the-'Well and' said 'airpiston drawing'` air throngh's'aid vertical passage check valvec and saidy airline` into saidivairfchamber, means connected with-fsa'idiwaterpiston and oprati'vupon cessation of water flow for=`moving said pston to 'force the' air inthe air chamber through 'the Vair 1in'e`, the lhorizontal passage -and theivcheck valve associated therewith-into said tankifsaid'vvater piston having therein ports throughy which Waterfniay now from the tank into s'ai service Iline l'as fsaid Water `piston approaches said abutment, and said piston further having REFERENCES CITED The following references are of record the le of this patent:

UN'ED "sfrATEv's PATENTS y A NumberA 'Name Date-- 1,612,017 Hastings Dep. 28, 1926 20 2,416,345 Piccardo Feb.v 25, 1947 

